[securemail] Update Composer dependencies

- Update phpseclib/phpseclib to version 2.0.4
- Update singpolyma/openpgp-php to version 0.3.0

securemail/vendor/singpolyma/openpgp-php/examples/verify.php

@@ -0,0 +1,18 @@
+<?php
+
+require_once dirname(__FILE__).'/../lib/openpgp.php';
+require_once dirname(__FILE__).'/../lib/openpgp_crypt_rsa.php';
+
+/* Parse public key from STDIN */
+$wkey = OpenPGP_Message::parse(file_get_contents('php://stdin'));
+
+/* Parse signed message from file named "t" */
+$m = OpenPGP_Message::parse(file_get_contents('t'));
+
+/* Create a verifier for the key */
+$verify = new OpenPGP_Crypt_RSA($wkey);
+
+/* Dump verification information to STDOUT */
+var_dump($verify->verify($m));
+
+?>